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Projektovanje izgradnje i testiranje 9``x 9`` NaI(Tl) spektrometra oblika jame / Design,construction and testing 9``x 9`` NaI(Tl) well typespectrometerHansman Jan 10 July 2015 (has links)
<p>Predmet istraživanja doktorske disertacije je konstruisanje,izgradnja<br />i uvođenje u rutinski rad, kao i naučna istraživanja detektorskog<br />sistema, kome će kao osnova poslužiti 9``x 9`` NaI(Tl) spektrometar<br />oblika jame. Pomenuti detektorski sistem će zbog veličine aktivne<br />zapremine kao i njenog specifičnog oblika (oblika jame) posedovati<br />najveću efikasnost detekcije u poređenju sa svim <br />gamaspektrometrijskim sistemima trenutno u upotrebi u Laboratoriji<br />za nuklearnu fiziku, Prirodno-matematičkog fakulteta, Univerziteta u<br />Novom Sadu i šire. Gamaspektroskopija je nedestruktivan metod<br />koji se može primeniti za određivanje niskih aktivnosti uzoraka bez<br />prethodne hemijske pripreme i predstavlja zlatni standard u<br />radioekološkim istraživanjima,kontroli životne sredine itd.<br />Detektorski sistem velike efikasnosti koji je tokom izrade doktorata<br />166 pušten u rad, omogućuje značnu redukciju vremena merenja kao i<br />sniženje minimalnih detektabilnih aktivnosti. Na ovaj način je Laboratorija za nuklearnu fiziku dobila detekcioni sistem pomoću kojeg je moguće vršiti analizu uzoraka niske aktivnosti u naučne svrhe kao i za rutinsku kontrolu uzoraka iz životne sredine.<br />Za upotrebu 9``x 9`` NaI(Tl) spektrometra oblika jame u rutinskim<br />merenjima radiološke kontrole uzoraka niskih aktivnosti, izvršena je<br />neophodna adekvatna kalibracija efikasnosti detektorskog sistema i<br />to na razne oblike matrica uzorakai na taj način su rezultati merenja<br />načinjeni uporedivim sa akreditovanim poluprovodničkim sistemima<br />Laboratorije za nuklearnu fiziku.</p> / <p>Subject of doctoral dissertation research is the design, construction and implementation in routine work, as well as scientific research of detector system, as the basis on well-type 9``x 9`` NaI (Tl) spectrometer. The aforementioned detector system, due to the size of the active volume as well as its specific form (well) possess the highest detection efficiency compared with all gammaspectrometric systems currently in use at the Laboratory of Nuclear Physics, Faculty of Science, University of Novi Sad and beyond. Gammaspectroscopy is a non-destructive method that can be applied for the determination of low activity samples without chemical preparation and is the gold standard in radioecological studies, environmental control and so on.</p><p>The detector systems high efficiency, which was during the preparation of doctoral dissertation put into operation, allows significant reduction in measurement time as well as lowering the minimum detectable activity. In this way, the Laboratory for Nuclear Physics get detection system which can be used for the analysis of samples of low activity for scientific purposes as well as for routine control of environmental samples.</p><p>For use well type 9``x 9`` NaI (Tl) spectrometer in routine measurements of radiological samples of low activity, there was a need adequate calibration of the detector efficiency of the system with various forms of sample matrix thus the results of measurements made comparable with accredited semiconductor <br />systems in Laboratory for Nuclear physics.</p>
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The folk religion of Ban Nai, a hamlet in Central ThailandKingkæo ʻAtthākō̦n, January 1967 (has links)
Thesis--Indiana. / "Folklore texts from Ban Nai": p. [187]-581. Vita. Bibliography: p. [591]-596.
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Characterization of wound monitoring systems used to quantify and locate plutonium contaminationDimmerling, Paul James 15 May 2009 (has links)
When an accident involving the possibility of a plutonium contaminated wound
occurs, the contamination is often quantified using sodium iodide (NaI(Tl)) and high
purity germanium (HPGe) detection systems. The NaI(Tl) system is used to quantify the
amount of contamination, while HPGe is used to gauge the depth of contamination in the
wound. Assessment of plutonium contaminated wounds is difficult due to the lowenergy
and yield of the uranium L-shell x rays used for the measurement, which can be
effected by source distance, shape, and tissue attenuation. These effects on wound
counting systems used at Los Alamos National Laboratory (LANL) were characterized
experimentally using common source shapes (disk, point, and line) and acrylic plastic as
a tissue substitute. Experiments were conducted to characterize detector responses as a
function of tissue attenuation, source distance, and source depth in tissue. The computer
code MCNP5 was used to model both systems for wound counting and better examine
angular displacement of a line source in tissue.
The NaI(Tl) detector response was characterized using absolute detector
efficiency for all experimental measurements. Measurements showed that the NaI(Tl) system is significantly effected by the source to detector position and depth in tissue.
Characterization of the HPGe detection system was done utilizing the peak-to-peak ratio
from the two low-energy x rays. HPGe peak-to-peak ratios were not affected by source
to detector distance, but showed an increased response to source depth in tissue. MCNP
results suggested that small incident angles from the plane of the detector face can cause
significant effects on the response of both detectors. In summary, the response of both
systems showed dependence on source geometry and depth of contamination in tissue.
Correction values and uncertainties were determined based on these dependencies.
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A rapid, reliable methodology for radionuclide characterization of wet or dry stored used nuclear fuel via the application of algorithm-enhanced scintillator survey spectraPaul, Jessica Nicole 21 September 2015 (has links)
The growing concern regarding regulation and accountability of plutonium and SNM produced in commercial and research nuclear reactor fuel has driven the need for new spent nuclear fuel characterization methods to enable quantification and qualification of radioisotopes contained in used fuel in a reliable, quick, and inexpensive manner, with little to no impact on normal reactor operating procedures. This research aims to meet these objectives by employing advanced computational radiation transport methods incorporated into an algorithm to post process scintillator detector data gathered from used nuclear fuel in a spent fuel pool or in air. An existing, novel post processing algorithm, SmartID, has been updated to extract and identify unique photopeaks represented in the underwater environment for pool cooled used fuel. The resulting spectral data will be post-processed using an updated SmartID algorithm folded with deterministic adjoint results to render both qualitative and quantitative fuel content and irradiation estimates. This work has much significance to the nuclear power industry, safeguards, and forensics communities, since it yields this information at room temperature for a relatively low cost.
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姚鼐古文硏究. / Yao Nai gu wen yan jiu.January 1985 (has links)
馬淑翬. / 複本為複印本. / Thesis (M.A.)--香港中文大學硏究院中國語文學部. / Fu ben wei fu yin ben. / Includes bibliographical references (p. 1-14 (3rd group)) / Ma Shuhui. / Thesis (M.A.)--Xianggang Zhong wen da xue yan jiu yuan Zhongguo yu wen xue bu. / Chapter 第一章 --- 前言 --- p.1 / 注釋 --- p.11 / Chapter 第二章 --- 姚鼐古文淵源 --- p.13 / Chapter (一) --- 韓柳歐曾文道思想 --- p.14 / Chapter (二) --- 歸方與義法 --- p.40 / Chapter (三) --- 劉大櫆神氣音節說 --- p.66 / 小結 --- p.78 / 注釋 --- p.79 / Chapter 第三章 --- 姚鼐之文學理論 --- p.93 / Chapter (一) --- 義理、考證與文章之關係 --- p.94 / Chapter (二) --- 神理氣味格律聲色說 --- p.110 / Chapter (三) --- 陰陽剛柔說 --- p.149 / 注釋 --- p.162 / Chapter 第四章 --- 古文辭類篹之編纂及流響 --- p.175 / Chapter (一) --- 《古文辭類篹》編纂源起 --- p.175 / Chapter (二) --- 《古文辭類篹》版本 --- p.179 / Chapter (三) --- 《古文辭類篹》簡介 --- p.189 / Chapter (四) --- 《古文辭類篹》名稱辨正 --- p.198 / Chapter 甲 --- 古文不得為「文」辨 --- p.199 / Chapter 乙 --- 古文辭之「辭」字辨析 --- p.207 / Chapter 丙 --- 古文辭類篹之「篹」字辨正 --- p.212 / Chapter (五) --- 古文辭類篹之流響 --- p.219 / Chapter 甲 --- 《經史百家雜鈔》 --- p.222 / Chapter 乙 --- 《續古文辭類篹》王先謙本 --- p.225 / Chapter 丙 --- 《續古文辭類籑》黎庶昌本 --- p.227 / Chapter 丁 --- 《古今文鈔》 --- p.232 / Chapter 戊 --- 《新古文辭類篹》 --- p.233 / 附錄:各書分類簡表 --- p.236 / 注釋 --- p.237 / Chapter 第五章 --- 姚鼐古文選論 --- p.248 / 姚鼐古文分軆選論 --- p.254 / Chapter 1 --- 論議 --- p.257 / Chapter 2 --- 考 --- p.266 / Chapter 3 --- 序跋 --- p.268 / Chapter 4 --- 書 --- p.277 / Chapter 5 --- 贈序、壽序 --- p.287 / Chapter 6 --- 策問 --- p.297 / Chapter 7 --- 傳贊 --- p.299 / Chapter 8 --- 碑文、墓誌銘 --- p.307 / Chapter 9 --- 記 --- p.311 / Chapter 10 --- 賦 --- p.318 / Chapter 11 --- 哀祭 --- p.318 / 小結 --- p.320 / 注釋 --- p.323 / Chapter 第六章 --- 姚鼐古文影響 --- p.339 / Chapter (一) --- 姚門四大弟子 --- p.343 / Chapter 甲 --- 方東樹 --- p.343 / Chapter 乙 --- 管同 --- p.357 / Chapter 丙 --- 劉開 --- p.367 / Chapter 丁 --- 梅曾亮 --- p.378 / 私淑艾者 --- p.389 / 小結 --- p.401 / 注釋 --- p.404 / Chapter 第七章 --- 後記 --- p.417 / 注釋 --- p.428 / 附錄:姚鼐生平簡表 --- p.429
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The transfiguration of the 'four great strange books' = Si da qi shu bian rong kao xi /Hung, Tao. January 2000 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references (leaves 450-509).
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FEASIBILITY OF MEASURING SELENIUM IN HUMANS USING IN VIVO NEUTRON ACTIVATION ANALYSISSyed, Nasir Ahmed Tahir 06 1900 (has links)
Selenium (Se), an essential trace element, plays an important role in the normal function of a number of Se-dependent biological processes. Many studies have demonstrated that selenium deficiency in the body may contribute to an increased risk for certain neoplastic diseases (including colonic carcinoma, gastric carcinoma, pulmonary carcinoma and prostate carcinoma), as well as diseases of the cardiovascular, osseous, nervous systems and retardation of bone formation. However, at higher concentrations Se is cytotoxic. For these reasons it is desirable to have a means of monitoring selenium concentration in humans.
The feasibility of measuring selenium in humans using the in vivo neutron activation analysis (IVNAA) technique was studied. For this purpose human hand tissue equivalent phantoms were prepared with varying amounts of selenium and irradiated by a low energy neutron beam produced by the 7Li(p,n)7Be reaction by employing the high beam current Tandetron accelerator. The counting data saved using the 4π NaI(TI) detection system in anticoincidence, coincidence and singles modes of detection were analyzed. The selenium was detected via the neutron capture reaction, 76Se(n,γ)77mSe, whereas calcium was detected through the 48Ca(n,γ)49Ca reaction.
The peak areas of Se and Ca were computed and the Se concentrations were normalized to the Ca concentrations for various time segments of detection. The calibration lines were drawn between Se/Ca concentration and Se/Ca counts ratio. The minimum detection limits (MDL) were obtained and the inverse variance weighted mean value of MDL was finally calculated for three time segments. During the analysis of counting data it was also found that 18O is activated in water phantoms and becomes short lived radioactive 19O having T1/2=26.9 s.
To the author’s best knowledge, this study for the first time presents the MDL value in terms of Se/Ca concentration for the human hand bone equivalent phantom obtained from in vivo neutron activation analysis and these results will provide a good basis for future investigations. / Thesis / Master of Science (MSc)
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Monitoração de trabalhadores expostos à radiação natural em minas no Seridó do nordeste brasileiroSPACOV, Isabel Cristina Guerra 09 December 2016 (has links)
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Previous issue date: 2016-09-09 / A Província Pegmatítica da Borborema no Nordeste é uma das mais importantes áreas
geoeconômicas do Brasil. A atividade de mineração, entretanto, pode elevar a exposição de
trabalhadores do setor, às radiações ionizantes. A exposição às radiações no setor mineral
depende de uma série de fatores, incluindo o tipo de mina e geologia local, com elevadas
concentrações de radionuclídeos que compoem as séries do 238U e do 232Th. Este trabalho teve
como objetivo realizar a dosimetria radiométrica ambiental externa, estimando a taxa de dose
efetiva em doze minas de extração de caulim, granito, feldspato e scheelita, localizadas nos
municípios de Junco do Seridó-PB, Salgadinho-PB, Santa Luzia-PB, São José do Sabugi-PB,
Equador-RN e Santana do Seridó-RN. O monitoramento foi executado utilizando um
espectrômetro gama portátil NaI(Tl) e BGO, com medições realizadas no ar e os resultados
obtidos foram comparados a dose efetiva média mundial da exposição à fontes naturais de
radiação, de 2,40 mSv/a, baseada no relatório da UNSCEAR. O valor obtido da média
aritmética das taxas de doses efetivas foi de 3,34 mSv/a e desvio padrão de 2,47 mSv/a para
as minas em conjunto, estando acima do valor de referência mundial, bem como as taxas de
doses efetivas das minas de granito (5,80 mSv/a), feldspato (3,28 mSv/a) e scheelita (2,80
mSv/a). Com base nesse estudo, foi evidenciada uma maior radioatividade ambiental na mina
de granito (E), em Santa Luzia-PB (11,60 mSv/a), estando superior, cerca de cinco vezes, ao
valor de referência mundial. É, portanto, considerada uma área de elevado backgound natural,
com taxa de dose variando de 5 a 20 mSv/a, assim como a zona rural de São José de
Espinharas-PB, onde se encontra a jazida de urânio com média de 10,83 mSv/a, ambos na
região do Seridó. Por sua vez, apesar do valor médio da taxa de dose efetiva das minas de
caulim (1,78 mSv/a) estarem abaixo do valor de referência mundial, a caracterização
radiométrica da mina de caulim (D) em Salgadinho-PB, se faz necessária, tendo em vista o
valor de 2,94 mSv/a. Desta forma, recomenda-se também, estudos epidemiológicos de casocontrole,
coorte e correlação geográfica, que tratem de padrões, causas e quantificação dos
valores obtidos na dosimetria ambiental deste estudo, bem como da relação da incidência e
prevalência das doenças causadas pela exposição em áreas de elevado background natural. / The Pegmatitic Borborema Province located in the Northeast of Brazil, is one of the most
important geo-economic areas in the country. The mining activity, however, can increase the
exposure of workers to ionizing radiation. Exposure to radiation in the mineral industry
depends on a number of factors, including the type of mine and local geology, with high
concentrations of radionuclides which compose the series of 238U and 232Th. This study aimed
to carry out the external environmental radiometric dosimetry, estimating the effective dose
rate in twelve mines of kaolin, granite, feldspar and scheelite extraction, located in Junco do
Seridó-PB, Salgadinho-PB, Santa Luzia-PB, São José do Sabugi-PB, Equador-RN and
Santana do Seridó-RN. The monitoring was performed using a spectrometer portable gamma
NaI(Tl) and BGO, with measurements in the air and the results were compared to the global
average effective dose of exposure to natural sources of radiation of 2.40 mSv/y, based on the
UNSCEAR report. The obtained value of the arithmetic mean of the effective dose rate was
3.34 mSv/y from the twelve mines, being above the global reference value, as well as the rates
of effective doses of granite mine (5.80 mSv/y), feldspar (3.28 mSv/y) and scheelite (2.80
mSv/y). Based on this study, greater environmental radioactivity in granite mine (E) was
observed in Santa Luzia-PB (11.60 mSv/y), being higher, about five times to the global
reference value. It is therefore considered an area of high natural background with dose rate
ranging from 5 to 20 mSv/y, as well as the São José de Espinharas-PB, where the uranium
deposit is located, with an average of 10.83 mSv/y, both in the Seridó region. Meanwhile,
although the average value of the effective dose rate of kaolin mine (1.78 mSv/y) is below the
world reference value, the radiometric characteristics of the kaolin mine (D) Salgadinho-PB
are necessary, in view of the value of 2.94 mSv/y. Thus, also recommended are studies,
epidemiological case-control, cohort and geographical correlation, to address patterns, causes
and quantization of values obtained in the environmental dosimetry of this study, as well as
the relationship of the incidence and prevalence of diseases caused by exposure in areas of
high natural background.
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[en] IMPLEMENTACION OF A 4(PI )(GAMA) SYSTEM, WITH WELL TYPE NAI(TI) DETECTOR, FOR CALIBRATION OF GAMMA EMITTERS RADIONICLIDES / [pt] IMPLANTAÇÃO DE UM SISTEMA 4(PI)(GAMA), COM DETECTOR DE NAI(TI), TIPO POÇO, PARA A CALIBRAÇÃO DE RADIONUCLÍDEOS EMISSORES GAMADOUGLAS CISNEIROS DE BARROS 06 November 2001 (has links)
[pt] Os métodos de calibração absoluta para a determinação da
atividade de radionuclídeos mais utilizados nos
laboratórios de metrologia são o 4(Pi Beta - Gama)
(contagem de coincidências), pico-soma (coincidência
Gama - Gama ou X- Gama), o 4(PI,Gama) e o contagem em
ângulo sólido definido.O método 4(PI Gama) é
especialmente indicado na medição da atividade de
radionuclídeos que apresentam esquema de decaimento
complexo. Ele se baseia no cálculo da eficiência total do
sistema de medição para um determinado radionuclídeo,
através dos valores da eficiência total referente a cada
raio gama do esquema de decaimento do mesmo
radionuclídeo. Este cálculo é expresso, para um ramo do
decaimento, pela equação: EpsilomT = 1 - Produtório ( 1 - EpsilomTi )
(Confirma símbolos no resumo na tese) , onde EpsilomT é a
eficiência global para cada decaimento em cascata e EpsilomTi a
eficiência total para cada transição gama da cascata. A
equação completa leva em conta o número de ramos e a
probabilidade de cada raio gama. Os (Confirmar os
símbolos no resumo na tese)Ti são obtidos a partir da
curva eficiência x energia do sistema.O método do pico-
soma é aplicado na determinação da atividade para fontes
emitindo pelo menos dois raios gama subsequentes.
Neste trabalho é apresentado o procedimento experimental,
após a implementação dos métodos 4(Pi Gama) e pico-soma
no Laboratório Nacional de Metrologia das Radiações
Ionizantes - LNMRI, com a finalidade de expandir os
serviços de fornecimento de fontes radioativas aos
usuários, tanto em quantidade quanto em faixa de
atividade ampliada.Os padrões radioativos utilizados no
levantamento da curva de calibração eficiência total x
energia, na aplicação do método pico-soma e na validação
do método 4(Pi) foram: 241Am, 210Pb, 54Mn, 57 Co, 60Co ,
109Cd, 113Sn, 134Cs, 137Cs, 139 Ce e 88Y. Para verificar o
desempenho dos métodos implantados, foram calibrados os
radionuclídeos: 139 Ce, 60Co, 88Y e 134Cs, e comparados
com os valores padronizados com o sistema absoluto 4 (Pi
beta - gama). Os resultados encontrados foram
consistentes com os obtidos pelo método de padronização
absoluta 4 (Pi beta - gama) . / [en] Among the absolute calibration methods for activity
quantity of radionuclides the most used in the metrology
laboratories are: the 4(Pi Beta - Gama) (coincidence
counting), defined solid angle counting, sum-peak (or Gama -
Gama coincidence) and 4(Pi Gama) method. The 4( Pi Gama)
method is appropriate to measure the activity of
radionuclides with complex decay scheme and its
implementation at Laboratório Nacional de Metrologia das
Radiações Ionizantes, commissioned by INMETRO from 1989,
will provide to the expansion of the jobs to supply the
users by standard radioactive sources.The determination of
activity can be made using calibration factor and/or the
efficiency curve. For the implantation of this calibration
method at LNMRI, after the selection of the detector and
the electronic instrumentation, the attainment of the
eficiency curve in function of gamma rays energy, standard
sources with one or two peaks each were used. The method is
based in (Epsilon)T = 1 - Produtórioi (1 - Ti) where EpsilonT is the total
efficiency for each radionuclide and EpsilonTi is the
efficiency for each gamma transition of this radionuclide.
The detector selected was a 8``x 8`` well type NaI(Tl), with
well dimensions 6`` deep and 3`` of diameter, from Harshaw The
standards sources used are: Am-241, Pb-210, Mn-54, Co-57,
Cd-109, Ce-139, Co-60, Na-22, Y-88 and Zn-65.
The preliminary results are consistent with the literature.
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Automated retrieval and extraction of training course information from unstructured web pagesXhemali, Daniela January 2010 (has links)
Web Information Extraction (WIE) is the discipline dealing with the discovery, processing and extraction of specific pieces of information from semi-structured or unstructured web pages. The World Wide Web comprises billions of web pages and there is much need for systems that will locate, extract and integrate the acquired knowledge into organisations practices. There are some commercial, automated web extraction software packages, however their success comes from heavily involving their users in the process of finding the relevant web pages, preparing the system to recognise items of interest on these pages and manually dealing with the evaluation and storage of the extracted results. This research has explored WIE, specifically with regard to the automation of the extraction and validation of online training information. The work also includes research and development in the area of automated Web Information Retrieval (WIR), more specifically in Web Searching (or Crawling) and Web Classification. Different technologies were considered, however after much consideration, Naïve Bayes Networks were chosen as the most suitable for the development of the classification system. The extraction part of the system used Genetic Programming (GP) for the generation of web extraction solutions. Specifically, GP was used to evolve Regular Expressions, which were then used to extract specific training course information from the web such as: course names, prices, dates and locations. The experimental results indicate that all three aspects of this research perform very well, with the Web Crawler outperforming existing crawling systems, the Web Classifier performing with an accuracy of over 95% and a precision of over 98%, and the Web Extractor achieving an accuracy of over 94% for the extraction of course titles and an accuracy of just under 67% for the extraction of other course attributes such as dates, prices and locations. Furthermore, the overall work is of great significance to the sponsoring company, as it simplifies and improves the existing time-consuming, labour-intensive and error-prone manual techniques, as will be discussed in this thesis. The prototype developed in this research works in the background and requires very little, often no, human assistance.
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